1989 MITSUBISHI GALANT Service Repair Manual

35-48SERVICE BRAKES - Anti-lock Braking System Troubleshooting
I IE-3When diagnostic trouble code “21 G SENSOR” is displayedI
[Explanation]
The ABS ECU outputs this diagnostic trouble code
in the following cases.
lOFF trouble turning G sensor OFF (It is judged
that the
G sensor continues to be OFF for more
than approximately 13 seconds except when the
vehicle is stopped or when there is stop light
switch input.
lWhen there is a broken wire or short circuit in
the harness for the
G sensor system.
ABSPOWERRELAY
MAIN FUSIBLEIGNITIONLINK @SWITCH (IG2)
G-SENSOR
q
ABS ECU
II21314 15161 ~/819110111l12l1P/14l15~~6l17l16~~19120121122123l24125l26l27128129/30131j32b3134(15~14AO702
Is G sensor normal?(Refer to P.35-132.)
NoReplace G sensor.
1 Yes
Remove the ABS ECUconnector and check atthe harness connector.
I
With the ignition key “ON”No m The harness between thedoes the voltage betweenG sensor and the ABS
terminal No.6
and ground
ECU is broken.
indicate battery voltage?
Yes
*
Repair harness.
Replace ABS ECU.
1 TSB Revision

SERVICE BRAKES - Anti-lock Braking System Troubleshooting35-49
1 E-4 1 When diagnostic trouble code “22 STOP SW” is displayed
[Explanation]
The ABS ECU outputs this diagnostic trouble code
in the following cases.
lStop light switch may remain on for more than
15 minutes without the ABS functions.
lThe harness wire for the stop light switch maybe open.
[Hint]
If the stop light operates normal, the ABS harness
wire for the stop light switch input circuit to the ECU
is broken or there is a malfunction in the ABS ECU.
SUB FUSIBLELINK 0
WITH
AUTO-CRUISE CONTROL
SWITCH -G
_.ABSECU
F-l
14A0663
Do the stop lights light up - Noand go out normally?~ Check the stop light re-lated circuit and repairproblem spots.
Yes
connect the ABS EC
connector and inspect at
the harness side connec-
When the brake pedal isNoHarness wire betweenpressed forcefully, does thevoltage between connectorstop light switch and ABSECU is broken.terminal No. 29 and groundindicate battery voltage?
Yes
1
Repair harness.
1
Malfunction of ABS ECU Replace ABS ECU.I

35-50SERVICE BRAKES - Anti-lock Braking System Troubleshooting
E-5
I I
When diagnostic trouble codes “41 SOL V FRONT L”, “42 SOL V FRONT R” OR “43
SOL V DRIFT” are displayed
I
[Explanation]
The ABS ECU normally monitors the solenoid valve
drive circuit. If no current flows in the solenoid even if the ECU
turns the solenoid ON or if it continues to flow evenwhen turned OFF, the ECU determines the solenoid
coil wire is broken/short circuited or the harness is
broken short circuited and then these diagnostic
trouble codes are output.
IGNITION
SWITCH
llG1)
HU
1 / 2 / 3 14 15 16 I 7 ~8~9h0~11~12~13~14~15[16[17@,19bO~21i22~3~24~25)26~27~28~29~30)31$2~33)34[35j
:Non-Turbo tor and check with the HU
side connector.
Connect HU IOP connec-tor, disconnect ECU con-nector and check.
Is the solenoid valve resis-tance value within the ranae
The harness wire for thesolenoid valvecircuit1
nectar?
Standard value: 1.0-l .3 Q
YesIRepair ABS harness.1
Replace ABS ECU.1
I1 TSB Revision

SERVICE BRAKES - Anti-lock Braking System Troubleshooting35-51
E-5When diagnostic trouble code “51 VALVE RLY” is displayed
[Explanation]
When the ignition switch is turned ON, the ABS
ECU switches the valve relay OFF and ON for an
initial check, compares the voltage of the signal to
the valve relay and valve power monitor line voltage
to check whether the valverelay operationis
normal. In addition, normally it monitors whether or
not there is power in the valve power monitor line
since the valve relay is normally ON. Then, if the
supply of power to the valve power monitor line is
interrupted, this diagnostic trouble code will output.
MAIN FUSIBLE$tW&N
LINK @I(IGl)
gEli!z$; lf*x**
IT
510
IU-412 &-,8
ABS ECU
: Non-Turbo . Turbo: Non-Turbo y+iw+w;,aay;check thy
When the valve relay i
s
checked, are the following
conditions found?No. 85-No. 86:resistance
value 60-120 52No.30-No.87a: continuity
No. 30-No. 87: No continui-
When battery voltage is ap- plied between terminals
No. 86 and No. 85 grounded.
No.30-No.87: continuity
No. 30-No. 87a: no continui-
t
y
remove the HU connec-
\/
I With
the
ignition key “ON”
,
No c HU power harness wire is
does the voltage betweenbroken?the connector terminal No.
12 and ground indicate bat- tery voltage? I
IRepair harness.
YesIIIbI\I
Does resistance between
body connector termina
l
No. 2 and terminal No. 27 in-
dicate
60-120 ohm?
IYes
Is there continuity between
body connector terminal No.
22 and ground? Repair harness.
ABS ECU malfunction Replace ABS ECU.
1 TSB Revision1

35-52SERVICE BRAKES - Anti-lock Braking System Troubleshooting
E-7When diagnostic trouble code “52 MOTOR RLY” is displayedI
[Explanation][Hint]
The ABS ECU outputs this diagnostic trouble code forIf there is motor operation noise when wheel speed
the motor relay and motor in the following cases. exceeds Gkm/h
(4mph) when starting up after the
l When the motor relay does not function engine is started, or when there is forced scan tool
l When there is trouble with the motor
itself and itdrive, there is a broken or short circuited motor
does not revolve monitor wire.
l When there is trouble with the motor itself and it
the motor does not revolve
l When the motor continues to revolve Yes
Broken wire or short cir-
-Inoise when wheel
speedcuit in motor monitor line
MAIN FUSIBLE
LINK @&
1 j 2 I3 I4 I5 I6 I 7 18 I9 l10l11112113114115116l17 1819p0~1122~3~24l2S~26I27(2~29130131l32l33l3~~3~
(Remove the motor relay>
r
l
-
\
/4~
Remove the motor relay and -check resistance values.No c Motor relay malfunction
No. 85-No. 86:resistance4
value 30-60
QNo.30-No.87: no continui-
Replace motor relay.
t
y
Battery voltage is applied on
terminals No.86
and
No.85groundedNo.30-No.87: continuity 1Yes
Is pump motor ground con-
No
netted normally?
Connect ground wire.
lYes
<
Install motor relay and
move HU connector.
Does voltage between body
connector terminal 11 and
No ) Broken wire in pum
p
ground indicate battery vol- motor power circuit
tage?
4
Yes Repair the harness.I
tor and
remove theECU
Is resistance between body - No - Malfunction of harness
connector terminal No. 2 andNo No.26
30-60 ohms? between HU and ECUI
4 Yes.
Repair harness.II
ABS ECU malfunction
Replace ABS ECU.I
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SERVICE BRAKES - Service Adjustment Procedures35-53
switch
switch
c/ 14F516
Pedal
Idown /
\ \
F14517
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F14518
SERVICE ADJUSTMENT PROCEDURES
BRAKE PEDAL INSPECTION AND ADJUSTMAN-
1.Measure the brake pedal height as illustrated. If the brake
pedal height is not within the standard value, adjust as
follows.
Standard value (A): 176-181 mm (6.9-7.1 in.)
(1) Disconnect the stop light switch connector, loosen the
lock nut, and move the stop light switch to a position
where it does not contact the brake pedal arm.
(2) Adjust the brake pedal height by turning the operating
rod with pliers (with the operating rod lock nut
loosened), until the correct brake pedal height is
obtained.
(3) After screwing in the stop light switch until it contactsthe brake pedal stopper (just before the brake pedal is
caused to move), return the stop light switch l/2
to 1
turn and secure by tightening the lock nut.
2.
(4) Connect the connector of the stop light switch.
(5) Check to be sure that the stop light is not illuminated
with the brake pedal unpressed.
Reference value
(B): 0.5-1.0 mm (.02-.04 in.)
With the engine stopped, depress the brake pedal two or
three times. After eliminating the vacuum in the power
brake booster, press the pedal down by hand, and confirm
that the amount of movement before resistance is met
(the free play) is within the standard value range.
Standard value
(C): 3-8 mm (.l-.3 in.)
If the free play is less than the standard value, confirm that
the clearance between the stop light switch and brake pedal is within the standard value.
If the free play exceeds the standard value, it is probably
due to excessive play between the clevis pin and brake
pedal arm. Check for excessive clearance and replace
faulty parts as required.

35-54SERVICE BRAKES - Service Adjustment Procedures
F14519
14UOO61
When engine isstopped
No good
0
w
\/‘14UOO62z;redengine
is
14UOO60 ,3.
Start the engine, depress the brake pedal with approxi-
mately 500 N (110 Ibs.) of force, and measure the clearance
between the brake pedal and the floorboard.
Standard value(D): 80 mm (3.1 in.) or more
If the clearance is less than the standard value, check for
air trapped in the brake line and for brake fluid leaks. If
necessary, check the brake system mechanism (excessive
shoe clearance due to faulty auto adjuster) and repair
faulty parts as required.
models>
4. After adjusting the height of the brake pedal, inspect the shift lock device.
5. If there is any trouble in the functioning of the shift lock device, adjust the shift lock cable.
NOTE
Refer to GROUP 23 for details about inspection and
adjustment of the shift lock device.
BRAKE FLUID LEVEL SENSOR CHECKM35F6A6
(1) Connect a circuit tester to the brake fluid level sensor.
(2) Move the float from top to bottom and check for
continuity.
(3) The brake fluid level sensor is in good condition if there is
no continuity when the float surface is above “A”, and if
there is continuity when the float surface is below “A”.
BRAKE BOOSTER OPERATING INSPECTION MlKcAJ
For simple checking of brake booster operation, carry out the
following tests.
(1) Run the engine for one or two minutes, and then stop it.
(2) Step on the brake pedal several’ times with normal
pressure.
If the pedal depressed fully the first time but gradually
becomes higher when depressed succeeding times, the
booster is operating properly.
If the pedal height remains unchanged, the booster is
faulty.
(3) With the engine stopped, step on the brake pedal several
(4
If
times with the same foot pressure to make sure that the
pedal height will not change.
Then step on the brake pedal and start the engine.
If the pedal moves downward slightly, the booster is in
good condit’on. If there is no change, the booster is faulty.
.) With the engine running, step on the brake pedal and then
stop the engine.
Hold the pedal depressed for 30 seconds. If the pedal
height does not change, the booster is in good condition.
If the pedal rises, the booster is faulty.
the above three tests are okay, the booster performance
can be determined as gooa.
If one of the above three tests is not okay at last, the check
valve, vacuum hose, or booster will be faulty.
CHECK VALVE OPERATION CHECKM3!3FNAK
cl989 models>
1. Remove the vacuum hose at the brake booster side.
2. Remove the check valve from the brake booster.
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SERVICE BRAKES - Service Adjustment Procedures35-55
Valve .,Spring
3rake)oostelside
14AO358
3.Check the operation of the check valve by using a vacuum
pump.
Vacuum pump connection Accept/reject criteria
Connection at the brake A negative pressure (vacuum) is
booster side
@Icreated and held.
Connection at the intakemainfold side @
A negative pressure (vacuum) is notcreated.

When checking the check valve, keep the check valve fit in the
vacuum hose.
1. Remove the vacuum hose.
Caution
The check valve is press-fit inside the vacuum hose and
do not remove the check valve from the vacuum hose.
2.Check the operation of the check valve by using a vacuum
pump.
Spring
Valve
14A0417
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Vacuum pump connection Accept/reject criteria
Connection at the brake A negative pressure (vacuum) is
booster side
@created and held.
Connection at the intake manifold side @
A negative pressure (vacuum) is notcreated.
Caution
If the check valve is defective, replace it as an assembly
unit together with the vacuum hose.